Introduction: Re3DP Trawl

About: Empowering citizen scientists to track and together prevent marine pollution.

The Re3DP Trawl is a DIY Trawl for Citizen Scientists to begin testing for plastic pollution in local waterways. Once the Trawl is assembled it can pulled behind a boat, dangled from a bridge or towed along the shoreline. Pollution collected can be shared to the website to help identify the source of pollution and ideally prevent it from entering the water in the first place.

The Re3DP Trawl is made from repurposed PETE plastic beverage bottles, held together by a 3D Printed Connector, preferably printed using filament made from recycled PETE plastic beverage bottles.

We are using part of the problem, single use plastic, to now take a small step toward a solution, through public engagement and action.

Total Re3DP Trawl material cost = <$15.

Begin building your own Re3DP Trawl today!

Step 1: Commit to Fighting Plastic Pollution in Our Waters!

In 2014, international scientists collaborated with to publish the first Global Estimate of Marine Plastic Pollution, and determined that 5.25 trillion particles of “plastic smog” surface pollution—weighing in at nearly 270,000 metric tons—pollute our oceans worldwide.

Plastic is now entering our oceans at the rate of a Garbage Truck a Minute.

At this rate, by 2050 there will be more Plastic Pound for Pound than Fish.

Help us engage the public by demonstrating how polluted our waters have become.

Help us prevent the plastic from entering the water by identifying the sources of pollution.

Help us Dispose of Disposables and Return to Reusables.

Step 2: 3D Print (3DP) Connector

Use the source CAD file from Fusion360 or the STL file to 3DPrint the Connector.

Study a 3D Visualization of the Re3DP Connector here.

Recycled PETE 3D printing filament available from

Step 3: Gather Materials

    The materials below can found at most hardware stores or ordered online.

    Parts available online are linked to vendors.

    Note: It is more important that the 2 Frames are the same length, whether they are longer or shorter than 12" is not as critical.

    Step 4: Inspect 3DP Connector

    • Remove any support material
    • Clear Frame cavity on 3DP connector
    • Clear Net Groove on 3DP connector
    • Clear Bottle Cap cavity on 3DP connector
    • Clear Frame attachment hole on 3DP connector, Repeat 1x
    • Repeat 1x

    Step 5: Drill Hole Into 2L Bottle Cap

    1. insert Bottle Cap into 3DP Connector
    2. Use hole in 3DP Connector to determine hole location in Bottle Cap.
    3. Drill 1/8" Hole into Bottle Cap
    4. Repeat 1x

    Step 6: Secure Bottle Cap Into 3DP Connector

    1. Insert Screw through Washer and 3DP Connector into Bottle Cap Hole
    2. Insert Washer and Nut under Bottle Cap onto Screw
    3. Tighten Screw
    4. Repeat 1x

    Step 7: Assemble Frame - First Time

    1. Insert Aluminum Frame into 3DP Connector
    2. Repeat 1x
    3. Attach remaining 3DP Connector onto 2 Frames already attached to 3DP Connector
    4. Ensure Bottle Caps are on same side

    Step 8: Drill Hole Into Frame

    1. Use Hole in 3DP Connector to determine Hole Location on Frame
    2. Remove Frame from 3DP Connector
    3. Drill 1/8" Hole in Frame
    4. Repeat 3x

    Step 9: Assemble Frame - Final Time

    1. Insert Aluminum Frame into 3DP Connector
    2. Repeat 1x
    3. Attach remaining 3DP Connector onto 2 Frames already attached to 3DP Connector
    4. Ensure Bottle Caps are on same side

    Step 10: Assemble Net

    1. Arrange Net on Net Groove around 3DP Connector.
    2. Align Net Seams beside Bottle Caps
    3. Insert Net through Center of Frame

    Step 11: Secure Frame and Net

    1. Insert Screw through Washer and 3DP Connector
    2. Puncture Net with Screw
    3. Insert Screw Through Net
    4. Thread Nut onto Screw Securing Net
    5. Tighten Screw
    6. Insert Nut into Hexagonal Nut Cavity on 3DP Connector
    7. Tighten Screw Completely
    8. Repeat 3x

    Step 12: Screw 2L Bottle Onto Bottle Cap

    1. Remove Beverage Label
    2. Clean Bottle
    3. Remove Bottle Cap Ring (if still attached)
    4. Screw 2L Bottle onto 3DP Connector
    5. Repeat 1x

    Step 13: Tie Rope Onto 3DP Connector

    1. Cut Rope to desired length
    2. Seal end of Rope (Flame, Glue, Crimp, etc)
    3. Tie Rope through holes in 3DP Connector (double square knot works well)
    4. Repeat 1x

    Step 14: Go Trawl!

    Put Trawl in the water:

    • Behind a Boat (slow speed)
    • Over a Bridge or Pier
    • Along a Shoreline

    Step 15: Share Your Results.

    After Trawling examine your findings in the Net.

    Share your experience and results with

    For processing your samples see Instructables: - Citizen Science Marine Pollution Data Processing is a project of Anthropocene.Design